In a conventional method for fabricating a laminated ceramic capacitor, a desired pattern of conductive paste consisting mainly of noble metal such as platinum (Pt) or palladium (Pd) is printed on a non-sintered ceramic sheet (green sheet) consisting of dielectric ceramic material powder. Then, a plural number of the green sheets are laminated and attached each other, and the laminated green sheets are fired at a temperature in the range of 1300.degree. C. to 1600.degree. C. under an oxidation atmosphere.
The non-sintered ceramic sheets consisting of dielectric ceramic sheets consisting of dielectric ceramic material powder become dielectric ceramic layers by firing the sheets, and the conductive paste consisting mainly of noble metal such as platinum or palladium become internal electrodes.
As described above, by adopting the conductive paste consisting mainly of noble metal such as platinum or palladium, a desired internal electrode can be obtained without oxidation thereof even if the material thereof is fired at a high temperature in the range of 1300.degree. C. to 1600.degree. C. under an oxidation atmosphere.
However, noble metals such as platinum or palladium are expensive, so that the laminated ceramic capacitors become essentially costly.
In order to resolve the problem described above, the applicant of the present invention has proposed in Japanese Patent Publication No. 61-14607, in which dielectric ceramic compositions including basic components consisting of (Ba.sub.k-x M.sub.x)O.sub.k TiO.sub.2 (M is Mg and/or Zn) and additional components consisting of Li.sub.2 O and SiO.sub.2 are disclosed.
Japanese Patent Publication No. 61-14608 has disclosed dielectric ceramic compositions including additional components consisting of Li.sub.2 O, SiO.sub.2 and MO (MO is one or more than one kind of metal oxides selected from a group consisting of BaO, CaO and SrO) instead of Li.sub.2 O and SiO.sub.2 in the cited reference No. 61-14607.
Japanese Patent Publication No. 61-14609 has disclosed dielectric ceramic compositions consisting of basic components consisting of (Ba.sub.k-x-y M.sub.x L.sub.y) O.sub.k TiO.sub.2 (M is Mg and/or Zn, and L is Sr and/or Ca) and additional components consisting of Li.sub.2 O and SiO.sub.2.
Japanese Patent Publication No. 61-14610 has disclosed dielectric ceramic compositions including additional components consisting of Li.sub.2 O, SiO.sub.2 and MO (MO is one or more than one kind of metal oxides selected from a group consisting of BaO, CaO and SrO) instead of Li.sub.2 O and SiO.sub.2 in the cited reference No. 61-14609.
Japanese Patent Publication No. 61-14611 has disclosed dielectric ceramic compositions consisting of basic components consisting of (Ba.sub.k-x M.sub.x)O.sub.k TiO.sub.2 (M is one or more than one kind of metals selected from a group consisting of Mg, Zn, Sr and Ca) and additional components consisting of B.sub.2 O.sub.3 and SiO.sub.2.
Japanese Patent Publication No. 62-1595 has disclosed dielectric ceramic compositions consisting of basic components consisting of (Ba.sub.k-x M.sub.x)O.sub.k TiO.sub.2 (M is one or more than one kind of metals selected from a group consisting of Mg, Zn, Sr and Ca) and additional components consisting of B.sub.2 O.sub.3 and MO (MO is one or more than one kind of metal oxides selected from a group consisting of BaO, MgO, ZnO, SrO and CaO).
Japanese Patent Publication No. 62-1596 has disclosed dielectric ceramic compositions including additional components consisting of B.sub.2 O.sub.3, SiO.sub.2 and MO (MO is one or more than one kind of metal oxides selected from a group consisting of BaO, MgO, ZnO, SrO and CaO) instead of B.sub.2 O.sub.3 and MO in the cited reference No. 62-1595.
By using one of the dielectric ceramic compositions disclosed in the cited references as a dielectric layer, a dielectric ceramic capacitor can be obtained by firing at a temperature up to 1200.degree. C. under a reducible atmosphere, in which a dielectric constant is at least 2000 and a dielectric constant change rate by temperature changes is in the range of -10% to +10% at a temperature in the range of -25.degree. C. to +85.degree. C.
Recently, electric circuits become high densed, which requires intensely miniaturization of ceramic capacitors, so that it has been expected to develop a ceramic capacitor including a dielectric ceramic composition which has a dielectric constant still larger than that of the dielectric ceramic compositions disclosed in the cited references shown above.
It has been also expected to develop a ceramic capacitor including a dielectric ceramic composition which has a relatively small capacitance change rate by temperature changes at a temperature in the range wider than that in the dielectric ceramic compositions disclosed in the cited references shown above.
Accordingly, it is an object of the invention to provide a ceramic capacitor including a dielectric ceramic composition which has a dielectric constant at least 3000, a dielectric loss tan (.delta.) up to 2.5%, a resistivity .rho. at least 1.times.10.sup.6 M .OMEGA..multidot.cm, and a dielectric constant change rate by temperature changes in the range of -15% to +15% at a temperature in the range of -55.degree. C. to 125.degree. C. (the standard is set at 25.degree. C.) and in the range of -10% to +10% at a temperature in the range of -25.degree. C. to 85.degree. C. (the standard is set at 20.degree. C.) by firing the composition even at a temperature up to 1200.degree. C. in a non-oxidation atmosphere, and a method for fabricating the same.